复制粘贴只对IE有用

<script type="text/javascript">
document.body.oncopy = function() {
 if (window.clipboardData) {
  setTimeout(function() {
   var text = clipboardData.getData("text");
   if (text && text.length>300) {
    text = text + "/r/n/n本文来自xxxx博客，转载请标明出处：" + location.href;
    clipboardData.setData("text", text);
   }
  }, 100);
 }
}
     </script>